Question

What do all cells use for energy? (APPLY ALL)
Responses

• Muscle contraction
• Muscle contraction

• Nerve activities
• Nerve activities

• Protein, lipid, carbohydrate synthesis
• Protein, lipid, carbohydrate synthesis

• Passive transport
• Passive transport

• Active transport

Answer 1

All cells use **adenosine triphosphate (ATP)** for energy. ATP is the primary energy currency of the cell and is utilized in various biological processes, including:

- **Muscle contraction**: ATP provides the energy necessary for muscle fibers to contract.
- **Nerve activities**: ATP is crucial for the propagation of nerve impulses and neurotransmitter release.
- **Protein, lipid, carbohydrate synthesis**: ATP supplies the energy needed for synthesizing macromolecules.
- **Passive transport**: Although passive transport does not require ATP, ATP is involved in maintaining gradients that enable passive transport processes.
- **Active transport**: ATP is essential for active transport mechanisms, which move molecules against their concentration gradient.

In summary, ATP is the common energy source that supports all these cellular functions.